Talking-machine reproducer



C. H. ALLEN ET AL TVALKING MACHINE REIRODUCER AApril s 1924.

Orignl Filled Aug. 25 1920 2f zz i a l! :ks

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To all whom t may concern:

Patented Apr. 8, 1924.

UNITED VSTATES PATENT OFFICE.

CHARLES H. .ALLEN AND CHARLES A.. MOORE, OF` CHICAGO, ILLINOIS.k

TALKIN G-MACHIN E REPRODUCER.

Application filed August 25, 1920, Serial No. 405,827.

Be it known that we, CHARLEsH. ALLEN and CHARLEs A. MOORE, Icitizens ofthel United States, and residents of the city of Chicago, in the countyof Cook and State of illinois, have invented certain new and use` fulImprovements in a Talking-Machine Reproducer; and wedo hereby declarethat the following is a full, clear, and exact description of the same,reference being had to the accompanying drawings, and to the numerals ofreference marked thereon, which form a part of this specification.

This invention relates to talking machines and more particularly to thereproducers thereof, with a View to improving the tone qualities and theadaptability of the machine. Hitherto it has been usual intalkingmachine construction to provide a diaphragm which covers the endof a tube leading toa horn, whereby sound waves are transferred to thehorn and therein amplilied. y In the vibration of such a diaphragm twosets of air waves are set into motion, one on each side of thediaphragm, but it will be seen that only one set of air waves isutilized, namely, those on that side of the diaphragm which pass intothe tube or amplifying horn, the duplicate set of air waves generated onthe opposite side of the diaphragm being. dissipated in the air andtherefore lost on account of their not being amplified. It willV beseen, therefore, that only a maximum of fifty per cent of all the airwaves generated. could be utilized in the reproduction of sound.

One of the objects of this invention, therefore, is the utilization of amaximum amount of the sound waves generated by a vibrating diaphragm byleadinga sound conducting tube from each side thereof. f

Hitherto most-of the reproducers used in phonographs were adapted toreproduce only one particular sort of vibrations from the record ordisk. As is well known, some ofthe records now in use employindentations for the transmission of sound which are in a horizontalplane or are wavy lines in the surfaceof the disk and other recordsemploy indentations which are made in a vertical plane in the disk andare undulatory. In other words, the production of' sound in some recordsis accomplished by means of vibrating 'the ypoint of the needle in ahorizontal or transverse plane, and in other records the point of theneedle is viitenewed Aug-ust 22,1923. y

` brated in a vertical'plane. Now, in vorder to `use both types ofrecords on one machine,

it vhas been hithertol necessary to shift they point of the needlethrough an angle of approximately degrees in order to attain the fullbeneiit from the vibrations which were produced in planes 90 degreesapart.

Another object of' this invention, therefore, is to produce a phonographreproducer which will reproduce sound from both records which ,havetheir vibrational impressions in horizontal yand in vertical planeswithout any shift of the needle or of the reproducer.

A still further object of this invention is the provision of an improvedform of reproducer whereby all the vibrations from the record or diskare transmitted directlyto the diaphragm, but'without imposing any unduestrainV on the diaphragm due to the weight of the reproducer or othercauses.

A further important object of this invention is to provide a phonographreproducer which can bev readily taken apart and which can be removedfrom the remainder of the reproducer assembly with a minimum of time andedort. p

Other and further important objects of this invention will be apparentfrom the disclosures in the speciiication and drawings. The invention(in a preferred form) is illustrated in the drawings and hereinafter`more fully described.

In the drawings: Figure l is a side elevation, partly in section, of ourimproved formof phonograph reproducer shown as applied to a disk record.r y l FigureQ is a rear elevation of the same, thJ tube to theamplifying horn being omitte ylligure 3 is a bottom plan'view of thesame. y `Figure 4 is a sectional view of the reproducer and of the tubeleading to they amplifying horn showing the method of attaching thereproducer to the tube.

, Figure 5 is a sectional view taken on the line 5-5 of Figure 4,looking lin the direction indicated by the arrows. "Figure 6 yis adetail view showing the method'of attaching the diaphragm to the pivotedneedle holder. 1

. i VAs' shown on the drawings:

from the reproducer to the amplifyin horn. However, Vin thisconstruction 'the tu e terminates in two branches 12 and 14, which aremade in the shape of a U and the ends of which are adapted to itintocorresponding tubular portions 16 and 18 in the reproducer member. It isto be noted that the sum of the sectional areas of the tubes 12 Aand 14is equal to the area of the horn 10 at the point of -junction therewithand from said point orn junction the horn gradually expands. Thisconstruction is a material factor in adding to the tonal qualitiesolf-the device. These tubular portions 16 and .18 are bent toward eachother in the reproducer and terminate in chambers 2O and 22respectively, one on each side of a diaphragm 24 located in the middleof the reproducen This diaphragm 24 is held in place by an ordinarypacking v26, through which passes screws 27 for holding the reproducerand diaphragm in assembled condition.

Attached to the diaphragm 24 by .means of a nut 28 is a pin or lightboltBO, which extends downwardly through the chamber and lower tube '18and out through a small aperture 32 in the reproducer. rfhe bolt isscrew-'threaded at its lend and adapted to screw into a needle-holdingmember 34, which ispivoted at 36 to two downwardly extendinglugs 88,which are integral with 'the bottom plate of -the reproducer.

The needle holding member 34 is provided with an ordinary knurled screw40 for thepurpose of holding the needle 42in position. Adjustably heldin place on the bottom of the reproducer by Lmeans of a screw 44, is alea-f spring-46, which rests upon 'the top of the needle holding member34 and coacts therewith to resiliently vsupport the same and thereby actto take part of the weight of the reproducing member vfrom thediaphragm.

The operation is asfollows:

The needle 42 is :placed in contact with the record or disk and therecord accordingly revolved, whereupon the needle will v be vibrated andsuch vibration will be transmitted to the diaphragm 24 through the baror pin' 30. Sound waves, upon being set up by thefvibration of thediaphragm v24, will be transmitted in both directions through they tubes16 and 18 and through the U-.s'haped member 12 and 14 into the Vmaintube 10, 7from which-they are delivered Ato the amplifying horn. It willbe .seen that in this manner no sound waves are dissipated in the air,all of them -which are generated by the motion of the diaphragmbeingretained in the reproducer and transmitted inthei`r full volume tothe amplifying horn by means of the tubes 16,118, 12, 14 and '10..

yIt will be seen that the needle 42 is so mounted that vibrationsof itspoint in either p a horizontal or a vertic'a-ljplane' willbetra'nsmitted to the diaphragm 24 with equal ease regardless of theplane in which the depressions in the record are produced. AnyVibrations in a vertical plane will be trans- 'mittedin Verticalwaves-directly through the needle 42, the needle holding member 34 andthe bar 30 to the diaphragm 24. Likewise vibrations in a horizontalplane Will be followed by the point of the needle 42, making it vibratein a horizontal plane. These vibrations will be along an arc loi? thatcircle which has its-center at the pivot point 36 and will accordinglybe transmitted through the bar orpin 30 to the diaphragm 24 in-practically the same manner as vibrations resulting irom-depressionsVin the record which have their wave lines ina horizontal plane.

It will further be noted that the weight of the reproducer, which wouldordinarily be entirely supported by the diaphragm 24, is taken up by thespring 46, which thereby Vsupports the reproducer through Vthe needleholding member 34. Should the tension in the spring 46 become lessened,.it can easily 'be adjusted by means of therscrew 44, thereby taking allor partofthe weight of the reproducer, accordingly as desired.

It -will be seen that herein is provided fa phonograph reproducer whichis Vadapted, to reproduce notesfrom records in which .the sounds wererecorded by means otarecording needle, the Vpoint of which vibrated .ineither a horizontal Y or a vertical plane. Usually a record which hashad its notes recorded thereon by means of a recorder thepoint of whichvibrates in a horizontal plane cannot have its sound reproduced by meansof a reproducen whose point will vibrate in only a vertical plane, andit therefore becomes necessary to shift the-reproducingvneedle throughan--arc or angle of vapproxi-mately 90 degrees in order to accommodatethe needle to the vibrations which were recorded in the other disk orrecord. It will further be seen that the entire weight of the reproducerand part of the weight of the horn 10 can be supported'by mea-ns of thespring 46, the whole or-part of the weight of these partsbeing taken oil`the diaphragm, which would otherwisesupport them, according-to thetension in-the spring which is adjusted by mea-ns of the screw 44according to the will of the operator. It will likewise be observedythat all of the sound waves propagated from 'the diaphragm are retainedwithin the tubes 16 and 18 and'transmitted through the tubes 12, 1`41and10 into the amplifying horn, which is not the case with Iany of thereproducersn'ow on the market, in which at least half ofthe sound wavesproduced are dissipated in the air and wasted on'aceount of the factthat the sound carrying tubeis located on onlyone side of the diaphragm,

` whereby a maximum of only 50 per cent of the sound Waves pro agated bythe diaphragm can be taken a vantage of.

We are aware that numerous details of construction may be varied througha wide range without departing from the principles of this invention,and we therefore do not purpose limiting the patent granted otherwisethan necessitated by the prior art.

We claim as our invention:

In a phonograph reproducer, a pivot parallel to the plane of the recordand to the direction of travel thereof, an arm on said pivot, the armbeing approximately parallel to the plane of the record and at rightangles to the direction of travel of the record, a needle holder rigidwith said arm at right angles to the plane of the record, and aconnection for said arm to the diaphragm in line with the needle holder,the distance from the record to the arm when in position to bring theneedle against the record being approximately equal to the distance fromsaid pivot to the needle holder, whereby records of the undulating typeand records of the sinuous type can be played with equal effectiveness.

In testimony whereof, we have hereunto subscribed our names in thepresence of two subscribing witnesses.

CHARLES H. ALLEN. CHARLES A. MOORE.

Witnesses:

CARLTON HILL, EARL M. HARDINE.

